This invention relates to a tool for removing a used shock absorber from a vehicle. More particularly, this invention relates to a tool that can quickly, easily, inexpensively, and safely break a shock stem on a shock absorber to permit removal from the mounting bracket in which the shock absorber is mounted in the vehicle.
Shock absorbers have long been used for automotive and other types of vehicles to (1) absorb shock imparted to the vehicle's wheels by the road surface and (2) dampen oscillation of springs associated with the wheel mounting assembly. Typically, a shock absorber includes a cylindrical shock body, a shock stem extending outwardly from a piston mounted in the cylinder, and attachment devices for securing the shock stem and the shock body between the wheel assembly and the chassis of the vehicle. Thus, the end of the shock body opposite the shock stem will be attached to a lower mounting bracket that supports the wheel. The opposite end of the shock absorber, defined by the end of the shock stem, will be secured to an upper mounting bracket, which is rigidly attached to the chassis or frame of the vehicle. Usually, the external end of the shock stem is threaded and extends through the mounting bracket to be held in position in the mounting bracket by means of a lock nut threaded on the threaded external end of the shock stem. The mounting bracket commonly is located in a position which makes access very difficult for removal of the lock nut.
Like all mechanical devices, shock absorbers wear and deteriorate through use. For example, automobile shock absorbers often must be replaced after 30-40,000 miles of use of the automobile in which the shock absorbers are mounted. Thus, for many decades, the volume of shock absorber replacement business has been very large and there has been a correspondingly large financial incentive to develop a quick, easy, inexpensive, and safe way of removing worn shock absorbers from the vehicles in which they were used. Despite the existence of this financial incentive over the past four or five decades, the methods of removing used shock absorbers have remained very time consuming, cumbersome, dangerous, or expensive.
For example, one known prior art method of removing a used shock from the chassis mounting bracket requires holding the top of the stem in place (to prevent it from rotating) with a tool, such as a wrench, while simultaneously turning the lock nut with another tool until the nut is removed from the threaded end of the shock stem. Then the shock stem must be removed from the passage on the mounting bracket. The shock stem of a used shock absorber, however, is often rusted so severely that the nut cannot be twisted off of the threaded end of the stem without a great deal of effort. Indeed, frequently the rust is so severe that the nut cannot be twisted at all without stripping the threads on the shock stem, making it impossible to remove the nut by unscrewing it from the threaded end of the stem.
In an attempt to more effectively remove the nut from the rusted stem, special sockets have been designed to slide over the threaded end of the shock stem and grip the periphery of the nut. The sockets are then rotated by means of a socket wrench in order to twist the nut off of the rusted threaded end of the shock stem. Although such a special socket does provide much better gripping of the nut of the stem, the socket cannot avoid the problem of severe rust causing the nut when turned to simply strip the threads on the stem, making unthreading impossible. Moreover, even if the threads on the stem do not become stripped, the socket and nut are often very difficult to turn because of the location of the upper mounting bracket.
Another prior art method entails sliding one end of a tubular socket over the threaded end of the shock stem, inserting a metal rod, such as a screw driver, into the free end of the socket, and pushing the free end of the screw driver to apply torque to shock stem to break the shock stem at a point intermediate the lock nut and shock body. Because the tubular socket does not rigidly attach to the threaded end of the shock stem and the screw driver does not rigidly attach to the socket, the socket or screw driver or both can easily slip and move in an undesired and extremely unsafe manner. Such slippage can easily cause injury to the mechanic, as well as consume a good deal of time. Moreover, this method often causes damage to the socket or screw driver by subjecting them to excessive, unintended forces and contact with each other and the shock stem.
It is therefore an object of the present invention to develop a tool for easily, quickly, economically, and safely removing a shock absorber from a mounting bracket in a vehicle.
It is also an object of the present invention to provide such a tool that will not cause damage to the tool when force is applied to the tool in order to break a shock stem of a shock absorber while mounted in the mounting bracket on a vehicle.
It is a further object to provide such a tool that can be used to remove shock absorbers from a wide variety of vehicles regardless of the proximity of the mounting bracket to the body or other components of the vehicle.
It is yet another object to provide such a tool that has interchangeable parts, allowing use of the tool to remove shock absorbers having differing types and sizes of shock stems.
Another object is to provide such a tool that utilizes the minimum amount of material for economy in manufacturing and shipping while having sufficient strength to function as a lever arm to break the shock stem of a shock absorber.
An additional object is to provide such a tool in which the tool is easily and quickly adjustable to reach and remove shock stems from upper mounting brackets despite differing locations of the mounting brackets with respect to the vehicle bodies in differing types of vehicles.
There are other objects and advantages of my invention. They will become apparent from the description within.